1. Technical Field
The present invention relates to a circuit connection structure of an automobile door, mounted on a door trim of the automobile door, for controlling the various electric equipment, such as a power window mechanism.
2. Related Art
Various electronic equipments are mounted on a door trim which is an interior cover plate of a door panel of a car, and examples of such electronic equipments include: a power window drive mechanism for automatically opening and closing window glass; a power seat adjusting-mechanism for automatically adjusting the degree of inclination of a driver""s seat in accordance with the body build and posture of the driver; and a courtesy lamp mechanism for lighting a lamp in order to warn other running cars of the fact that a door of the car, stopped or parked at night, is open. The electronic equipment is connected directly or via an inner panel-side wire harness to a door control unit (ECU: electronic control unit).
Since the wire harness including wires or cables for feeding control signals to the electronic equipment is installed in a space or gap between the door panel and the door trim, the installing operation may be effected with a blind operation, and requires much time and labor. Therefore, there is a problem to reduce the time and labor required for the installation of the wire harness, when the electronic equipment is mounted on the car door. Recently, instead of wire harnesses including wires and cable, FPCs (flexible printed circuit board), have drawn attention, and have been extensively used. Such FPC (flat circuit member) is thin, lightweight and flexible, and can be arranged and installed efficiently.
FIG. 5 is a perspective view showing a door wire harness (a conventional flat circuit member including a FPC disclosed in JP 8-230585A) as seen from the inside of the passenger room of the car.
In this case, the flat circuit member 3 is installed in a space between a reverse side of a door trim 2 and a door panel 1. One end of the flat circuit member 3 is connected via electric connectors 4, 5 and 6 to respective switch units which output switch signals for effecting the on-off control of electronic equipment including a power window drive mechanism, a courtesy lamp mechanism and a power seat-adjusting mechanism. An electric connector 7 for inputting operating signals from the body side is mounted on the other end of the flat circuit member 3.
In the flat circuit member 3 as shown in FIG. 5, if the power window drive mechanism and the courtesy lamp mechanism are standard electronic equipment including a standard circuit and if the power seat-adjusting mechanism is an optical electric equipment including an optional circuit, the standard circuit and the optional circuit are formed integrally with each other and formed into a single circuit construction.
Therefore, the conventional technique, disclosed in the above publication, has the following problems:
(1) The single flat circuit member 3, including an FPC, is of such a construction that the standard circuit and the optional circuit are formed integrally with each other. Therefore, when the optional electronic equipment is changed in accordance with a change of the kind of car, this flat circuit member can not meet such switch layout change, and the whole of the flat circuit member, including the standard circuit, must be reformed, and this is uneconomical.
(2) The single flat circuit member 3 is extended and installed so that the electronic connectors 4, 5, 6 and 7, mounted on the one and other ends of the single flat circuit member 3, can be located adjacent respectively to the corresponding electronic equipment and switch units. Therefore, the overall length of the flat circuit member 3 is naturally large. If the circuit becomes longer, the risk of cutting of wires during the installation of the flat circuit member becomes higher. Therefore in view of this, the width of the circuit member must be increased in accordance with the increased length thereof in order to secure the necessary strength of the circuit member. As a result, the flat circuit member 3 has the excessively large width, which is uneconomical.
(3) When the flat circuit member 3 is long and wide, this is liable to cause a malfunction in a very weak-current circuit.
(4) When the flat circuit member 3 is long and wide, it is also necessary to protect and fix the important intermediate part of the circuit members 3 by protective casings. The use of such protective casings increases the number of the component parts and the time and labor for the assembling operation, and besides the short-circuiting of the circuit is liable to be caused by the protective casing.
(5) Each of the switch units of the electronic equipment, to which the flat circuit member is connected via the electric connectors 4, 5, 6 and 7, includes an electric circuit of a conventional construction formed by lead wires. Therefore, it is very cumbersome to connect the flat circuit member (FPC) 3 to this electric circuit. A connector structure is provided at this circuit-connecting portion, and therefore the number. of the component parts increases, and also the operation becomes complicated. Therefore, generally, the electronic equipment circuit can not be simplified, and the production cost and the assembling cost can not be reduced.
It is therefore an object of this invention to provide a circuit connection structure of an automobile door in which the mounting operation can be simplified and can be effected efficiently by simplifying the whole of the installed circuit to reduce to a minimum length in a way that the circuit for controlling standard electronic equipment and the circuit for controlling an optional electronic equipment are provided as separate, independent units, respectively.
The above object of the invention has been achieved by a circuit connection structure for various electric equipments mounted on a door trim of an automobile door, comprising:
a standard circuit unit including a first flexible printed circuit board provided with a first electric connector for connecting to another circuit, and said standard circuit unit including a first switch circuit member for controlling a standard electric equipment; and
an optional circuit unit including a second flexible printed circuit board provided with a second electric connector for connecting to another circuit, and said optional circuit unit including a second circuit.
In this construction, the standard circuit unit for controlling the standard electronic equipments and the optional circuit unit for controlling the optional electronic equipment are provided as separate units, respectively. Therefore, when the kind of car is changed, only the optional circuit unit can be easily exchanged, and can be post-mounted. In the conventional standard circuit/optional circuit-integral type, even the standard circuit is removed from the door trim although this standard circuit itself does not need to be removed. In the structure of the invention, however, such uneconomical operation is eliminated, and the operation for mounting the structure on the door trim is reduced, so that the efficiency can be enhanced.
In the invention, the optional circuit unit, corresponding to the selected kind of car, is exchangeably mounted on the door trim, and is combined with the already-mounted standard circuit unit in such a manner that the first and second electric connectors can be easily combined together by recess-projection fitting.
In this construction, when the kind of car is changed, the second electric connector, provided at the optional circuit unit, is combined with the first electric connector, provided at the already-mounted standard circuit unit, with a one-touch operation by recess-projection fitting, and by doing so, this structure can be handled easily-when connecting the electric connectors to the other circuit such as a door control unit (ECU; electronic control unit), and the efficiency of the assembling operation is enhanced.
In the invention, the first switch circuit member is integrally formed in a predetermined pattern on the first flexible printed circuit board, and the second switch circuit member is integrally formed in a predetermined pattern on the second flexible printed circuit board.
The conventional switch circuit members are in the form of a lead wire circuit, and therefore the complicated connector structure, as well as much time and labor, has been required for connecting this lead wire circuit to the flexible printed circuit board (body). In the invention, since the first and second switch circuit members are integrally formed in their respective patterns on the first and second flexible printed circuit boards, respectively, the provision of the connector structure is omitted, and the time and labor for this operation is saved.
In the invention, the standard electronic equipment is a power window mechanism and a courtesy lamp mechanism while the optional electronic equipment is a power seat mechanism, and the optional circuit unit for controlling the power seat mechanism is post-mounted on the door trim, and is combined with the standard circuit unit already mounted on the door trim.
In this specific example, the optional circuit unit for controlling the power seat-adjusting mechanism can be post-mounted on the door-trim, and can be combined with the already-mounted standard circuit unit for controlling the power window drive mechanism and the courtesy lamp mechanism.